Vapor lamp jacket



Nov. 21, 1944. KEI FER 1 2,363,109

VAPOR LAMP JACKET Filed April 1, 1942 Inventor: Lawrence R. kei++er by I His A'f'tor'neg.

Patented Nov. 21, 1 944 Lawrence R. Keiffer, Clev signor to General Elec ration of New York eland Heights, Ohio, astric Company, a corpo- Application April 1,1942, Serial No. 437,288

3 Claims.

My invention relates to vapor discharge lamps, and its principal object is to provide a simple, effective, inexpensive, readily attachable and detachable light-transmitting, heat-retaining enclosure or jacket for such lamps. Another object of my invention is to provide a vapor discharge lamp enclosure which is constructed and arranged to be supported by. the lamp and to constitute part of the lamp when so supported. A further object of my invention is to provide a simple mounting means for a light-transmitting, heat-retaining sleeve on a temperature sensitive, elongated lamp having bases secured to the ends thereof. Further objects and advantages of the invention will appear from the following detailed description of species thereof and from the drawing, in which:

Fig. 1 is a side, elevational, partly sectional view of a vapor discharge lamp unit embodying my invention;

Fig. 2 is a fragmentary, sectional, side-elevational view of one end of a lamp unit embodying. my invention, and i Fig. 3 is a sectional view of a species of support member useful in the lamp unit illustrated in Fig. 2.

Referring to Fig. 1 of the drawing, the lamp unit illustrated comprises an elongated, tubular fluorescent lamp I and a tubular glass sleeve ll surrounding the lamp Ill. The sleeve ll is.sup-

ported by annular support members l2 and I3 disposed on the bases I4 and I5, respectively, of the lamp Ill. The bases l4 and I5, which are somewhat smaller in diameter than the lamp envelope, are provided with a pair of contact pins 16 which support the unit and transmit electrical energy to the lamp electrodes I1 and I8 when inserted in suitable sockets, such as those disclosed in the U. S. Reissue Patent 21,545, issued August 2'7, 1940.

The lamp I0 is similar to those disclosed in the U. S. Patents 2,182,732, issued December 5,

1939, and 2,259,040, issued October 14, 1941, and

comprises an elongated, tubular, sealed glass envelope containing a starting gas, such as argon, at a few millimeters pressure and a small quantity of mercury IS. The widely spaced electrodes l1 and [8 of the lamp [0 carry material of low work function, such as barium oxide. The inner surface of the envelope is coated with fluorescent material, indicated by the broken line in the drawing, which emits visible light, under the in fluence of radiation from the electrically excited mercury vapor during operation of the lamp.

Lamps of this type are commercially available gether with the bases I4 and I5 of the lamp l0,

in various lengths and diameters and are designed to have maximum light output when the temperature of the lamp envelope is about 100 to 120 F. and the air temperature is about '70 to 80 F. Changes in the environment of the lamp which lower the temperature of the lamp envelope cause the light output to decrease. For example, when the air temperature about the lamp envelope is approximately 30 to F., the light output is then approximately only to 80 per cent of the light output of the lamp at air temperatures of about to F. Drafts and lower air temperatures cause further diminution in the light output of the lamp.

The sleeve II, the members l2 and I3, to-

constitute an enclosure or jacket for the lamp envelope which effectively reduces the dissipation of heat from said envelope. A separation of the order of about one-quarter men between the sleeve II and the envelope is preferred, though this may be varied somewhat for different conditions. When a separation of this order exists, the maximum light output of an enclosed lamp occurs at an air temperature of about 25 to 35 F.

The annular members or washers l2 and I3 preferably consist of compressible, flexible material, such as soft rubber, or other material capable of supporting the sleeve II on the bases l4 and l5 and of efiectively sealing the space between the envelope and the sleeve I l. The outer diameter of the members [2 and I3 is slightly larger than the inner diameter of the sleeve II and the inner diameter thereof is slightly smaller than the diameter of the bases l4 and Hi. 'The thickness of the members I2 and I3 is approximately the same as the width of the bases l4 and I5. The lamp unit is readily assembled byforc- .ing one of said members l2 and I3 onto one of the bases l4 and I5, inserting the opposite end of the lamp into the sleeve, forcing the memher I 2 or I3 mounted on the base into the end of the sleeve ll, so that all these elements are flush as shown in the drawing, and then forcing the other annular member into the space between the opposite base and the open end of the sleeve II. The members l2 and I3 are compressed between the sleeve ll and the bases l4 and [5. The

50 sleeve l l is thus firmly supported in a fixed, spaced position with respect to the lamp ID. The sleeve I l is readily removed from the lamp III by pushing against one of the bases of the lamp In with suflicient energy to force one of the members I! and I3 out of the sleeve III. This member is then removed from the base and the lamp pulled out oi. the sleeve.

The embodiment of my invention illustrated in Fig. 2 of the drawing is similar in all respects to that illustrated in Fig. 1 except for the shape of the annular support member 20 and the length of the sleeve II. In this embodiment, the annular'member 20 has a ring-shaped or annular slot therein which is indicated at 2i in the drawing. The depth of the slot is slightly morethan half the thickness of the member 20 and accommodates the end of the sleeve ii. The end portion of the sleeve Ii is embedded in or covered by the member i9 and is thus effectively protected from accidental contact with solid objects. The sleeve ii is slightly shorter than the corre spending sleeve shown in Fig. 1 so that the outer surfaces of the base and the support member are flush. It will be understood that the opposite end of the lamp is the same structurally as the end illustrated.

The support member 22 illustrated in Fig. 3 of the drawing is similar to that illustrated in Fig. 2 except that the surfaces 22 of the slot are serrated to give a better gripping action on the end portion of the sleeve ll. As pointed out above, this support member is useful in the embodiment of the invention illustrated in Fig. 2 of the draw- Fluorescent lamps now commercially available have an outer diameter of about one inch, about 1 inches, and about 2 inches. It is particularly advantageous to use a sleeve having a diameter of 1 /2 inches for the one-inch lamp, and

a sleeve having a 2 /8 inch diameter for the 1 /2 inch lamp since salvage tubing of the 1% and 2%; inch size may be used as sleeves by the manufacturer.

While I have described my invention in conjunction with a fluorescent discharge lamp, it will be understood that I contemplate its use with other lamps similarly sensitive to changes in envelope temperature; for example, lamps similar to that illustrated in Fig. 1, except that the coating of fluorescent material is omitted and the lamp envelope is pervious to the radiation having a wavelength of 2537 Angstrom units emitted by the mercury vapor discharge, are commercially available. My heat-retaining enclosure is also useful in conjunction with such lamps when the sleeve II is of material pervious to the desired radiation.

The sleeve ll may be partially coated with'refleeting material, such as silver or aluminum, for purposes of shielding and light control.

Fluorescent material may be disposed in or on the sleeve ii when used with lamps emitting radiation capable of exciting such material;

What I claim as new and desire to secure by Letters Patent of the United States is:

1. A lamp unit comprising in combination an elongated gaseous electric discharge lamp having a base attached to each end thereof, and a heat conservator comprising an elongated glass sleeve surrounding said lamp and coextensive therewith and supported at each end by a washer of resilient material compressed between each base and the adjacent end of the sleeve, said washers effectively sealing the space between said lamp and I sleeve, and said sleeve being imperforate so as to provide a dead air space around the lamp.

2. A lamp unit comprising in combination an elongated gaseous electric discharge lamp having a base attached to each end thereof, and a. heat conservator comprising an elongated glass sleeve surrounding said lamp and coextensive therewith and supported at each end by a washer of reslllent material tightly secured'to and around each base, each of said washers being of larger outer diameter than said sleeve and having an annular slot in one of its faces between its inner and outer peripheries, the ends of said sleeve being secured in said slots and enclosed within said washers, said washers effectively sealing the space between said lamp and sleeve.

3. A lamp unit comprising in combination an elongated gaseous electric discharge lamp having a base attached to each end thereof, and a heat conservator comprising an elongated glass sleeve surrounding said lamp and coextensive therewith and supported at each end by a washer of resilient material tightly secured to and around each base, each of said washers being of larger outer diameterthan said sleeve and having an annular slot with serrated surfaces in one of its faces between its inner and outer peripheries, the ends of said sleeve being secured in said slots and enclosed within said washers, said washers effectively sealing the space betweensaid lamp and sleeve.

' LAWRENCE R. KEIFFER. 

